Sharif Digital Repository

In the last decade, a great deal of attention has been paid to the study of synthesis of Nanoparticles, because of the widespread use of this material in applications involving Fuel cells and magnetic devices. In this thesis, we report some interesting features in the electrodeposition of metallic nanoparticles. The electrochemical phase formation of rhenium and nickel on the surface of P-Si (100) substrate plus morphological, topographical and fractal aspects of the accumulated surface were investigated in this research by means of chronoamperometry method and by utilization of AFM and SEM. The nucleation and growth mechanisms on silicon electrode are characterized using cyclic voltammetry... 

The extraction of molybdenum and rhenium from acidic solution produced by pressure leaching of molybdenite concentrate, using organophosphorus solvents has been investigated. First, extraction of molybdenum by Di-2-EthyHexyl Phosphoric Acid (D2EHPA) extractant dissolved in kerosene diluents was done. Extraction experiments were designed using Taguchi L16b orthogonal array. The effects of four factors: Shaking time, Organic solvent concentration, Organic to aqueous phase ratio, pH were studied in four levels. Optimum conditions occur at: shaking time: 35 min, organic solvent concentration: 30 volumetric percent, organic to aqueous phase ratio: 3, pH: 7 and molybdenum is completely extracted.... 

In this work, the recovery of rhenium from ferromolybdenum furnace outgoing dust in semi industrial scale was conducted. The ferromolybdenum furnace outgoing dust contains rhenium as major part and large amounts of molybdenum plus Iron and copper as impurities. An overall flow sheet, consist of leaching, solvent extraction and precipitation methods, was design to recovery and purification of rhenium. Firstly, ferromolybdenum furnace outgoing dust was subjected to leaching treatment by 10 g/L sulfuric as solvent at 85 C. Secondly, solvent extraction method was employed, using LIX984N 10 %vol, to separate copper from rhenium containing solution. The results of MacCab thiele diagram for... 

The current study was carried out to investigate the pressure oxidative leaching of the molybdenite concentrate in nitric acid to produce molybdic oxide (technical grade) and liquor containing entire rhenium of the concentrate and molybdenum. In the first step The Taguchi method was established to design and minimize the number of experiments. By using Taguchi orthogonal (L25) array, five parameters (time, temperature, oxygen pressure, pulp density and acid concentration) in 5 levels were selected for 25 experiments. Experiments were designed and carried out in a high pressure reactor in the presence of nitric acid as solvent and oxidizing agent for the molybdenite concentrate and its ReS2... 

In this study, molybdenum and rhenium extraction from alkaline solution of electro-oxidation leachinng of Sarcheshmeh molybdenite concentrate by solvent extraction using organophosphorous organic solvents, under different conditions has been investigated. The studied variables were organic solvent concentration, ratio of organic phase to aqueous phase and pH. Design Expert software and Central Composite Design method was performed to evaluate the effect of parameters and optimize recovery conditions. Molybdenum was extracted via Di-2-EthyHexyl Phosphoric Acid (D2EHPA) organic solvent diluted in kerosene initially, in order to reduce molybdenum ions interruptions during extraction of rhenium.... 

The synthesis, characterization, structural and computational studies of mononuclear Re(I) tricarbonyl complexes of 2,2'-bipyridine (2,2′-bpy) and 2,9-dimethylphenanthtroline (2,9-Me2Phen), [Re(CO)3(NN)(X)], where NN=2,2′-bpy,X=Br (1) and X=–ONO (3); NN=2,9-Me2 Phen, X=Br (2) and X= –ONO (4), were reported. The complexes characterized by crystallographic and spectroscopic methods and elemental analyses. In each complex, the Re(I) center showed the distorted octahedral geometry. Single crystal X-ray diffraction data revealed the endo-nitrito (κ1–ONO) coordination in complexes 3 and 4. It has been shown that the replacement of the bromo ligand in complexes 1 and 2, either by AgOTf/NaNO2 in a...